A Comparison and evaluation of Samarqndī’s Double Version of mixed Ḥaqīqī-Khārijī Syllogisms

Shams al-Dīn Samarqandī has authored two logical books Qisṭās al-afkār and its self-commentary Sharḥ al-Qisṭās, both of which have two versions on ḥaqīqī and khārijī propositions, which seem to be due to the change of Samarkandi's logical opinions about ḥaqīqī and khārijī propositions. In the first versions of both the books, the relations between the propositions are mere implication (ʿumūm wa khuṣūṣ muṭlaq), but in the second version, the relations change to denial of implication (ʿumūm wa khuṣūṣ min wajhin). Also, in the first version, Samarqandī presents a universal rule (ḍābiṭ) for taking conclusions from mixed syllogisms composed of ḥaqīqī and khārijī propositions. Indeed, the second version can be seen as correcting the first version. In this paper, we shall show that even though Samarqandī’s attempt corrected some faults in the first version, it leaves some others uncorrected. In addition, there are new objections to the second version which would not been forwarded to the first version. Therefore, none of the first and second versions provides a correct and complete analysis of the mixing of the categorical khārijī, ḥaqīqī and mental propositions.